Air conditioning apparatus



g- 4, 1942- I s. A. DURBIN 2,292,335

AIR CONDITIONING APPARATUS I Filed Aug. 27, 1941 2 Sheets-Sheet 1 THEE/1087,47"

Figl.

Ill

'- rbisemsmr mac lnverwtor'fl- His Attorney Aug. 4, 1942. 5, DURBIN. 7 2,292,335

AIR CONDITIONING APPARATUS I I Fild Aug. 27, 1941 2 Sheets-Sheet 2 Fig.2.

WEIHVOSTA 7' as 29 THEPMOSTAT mf/emasnr WEE/145737 Inventor: Stephen ADurbin,

His A torney.

Patented Aug. 4, 1942 PATENT O FI I .Arn coumrronmqnrrmrus Stephen A. Durbin, Philadelphia, re.- v Application August 27, 1941', seriamdioam I mm- -My invention relates to air conditioning" apparatusand particularly to such apparatus employing-a reversible refrigerating machine or heat pump for both heating and cooling the air in one or more enclosures.

rangementfor reversing the-machine may comi 1 prise suitable valves for reversing'the refrigerant (Ci. arr-3) tion of heat.

circuit of-ithe machine so that the evaporator becomes acondenser and the condenser an evaporator, or'the refrigerant circuit may be fixed and secondary fluid circuits-provided so that the f reversing operation may be accomplished without changing the-main refrigerant circuit. 2

When the outdooriair, orany other fluid niedium the temperature of'whioh varies according having an improved arrangement for supplying heat to the external heat absorbing element thereof. I

Another object of my invention is to provide an air conditioning apparatus including a heat pump and having an improved arrangement for utilizing the outside air for the absorption and dissipa- Another object of, inventionfiis-to provide an apparatus for conditioning the air in a plurality ofenclosures and including an improved arrangement for providing both heating and cool ing capacityin accordance with the load demands" of the several enclosures;

Another object of my invention is to provide an apparatus including a heat pump for conditioning the, air in a plurality of enclosures and havingan improved; arrangement for; changing to the-season of the year, is employed as a source a of heatand' as a heat dissipating. medium, it is obvious thatfithe temperature of the. medium 1 variessin a'direction opposite tothe'loaddemandy of thema'chine; During the'coolingseasonLthefl greater the cooling'load the higher is the tem-;, perature 'of the. outdoor air and the less the dif iere'ntiai of temperature betweenthe outdoor air.

and the outdoor heat exchanger, andduringthe heatingseason the greater the demand. for heating the lower is the temperature of the outdoor air and the less thedifferential of temperature between theoutdoor-heat exchanger and the outdoor air; 'It is, therefore, desir'ableto provide some, ar'rangeme'ntfor increasing the effectiveness' of the-heat exchange between the outdoor ,air'andrefrigerating machine to compensate for the increased load demand particularly when the temperature of the outdoor isnear that of the outdoor heat exchange-element. I .During certain seasons of the l in a building may require achangeof the air temperature opposite to that in otherrooms thereof.. 'For'exam ple, during the cooling season the sunmaybeshining on one sideof the building so that rooms on that side require cooling wh le rooms on the shady side ofthe building may re: quire heating, and during the heating season some roomson the sunny side of the'zb'uilding may require cooling.

year some rooms v the temperature of the air supplied to one or more of saidenclosures in a direction opposite to that of the change of tem'peratureyof the air supplied to another of said'enclosures.

Further objects andad'vantagesof my invention wilLbecome apparent as thepfollowing description proceeds and. the features of novelty which characterize my invention will be pointed ,out i with particularity in the claims annexed to and forminga part of this specification.

= For a better understanding of 'my invention reference-may be had to the accompanying drawings in which Fig. I is a diagrammatic view of an air conditioning system embodying my invention and Fig. 2 is-a diagrammatic view ofthe control for the air conditioning system shown in Fig. l; g I

. The air conditioning system shownin the drawings is arranged to condition the air for a plurality of rooms or other enclosuresin a building. Desired quantitiesof fresh and return air are mixed and supplied to a conditioner housing which is divided into two air'paths or chambers, each containing 'aheat exchange element, one the main heat transfer element and the other an auxiliary-element. Ducts are'provided so that air from each of the chambers is mixed and supplied to the separate roomsin proportions de- It is an object of my inventionto provide an air conditioning apparatus including a heat pump.

termined by thermostatic controls responsive to the temperatures of their respective rooms. A compression type'refrigerating machine, including an evaporator and condenser is employed as aheat pump and .is provided with a secondary circuit which may contain' water. brine, or-any other suitable medium for transferring heat between the evaporator and condenser elements of the refrigerating machine and the heat transfer elements in the conditioner and an external heat transfer element over which outdoor air is circulated. During the cooling season the secondary circuit supplies cooling medium to the main heat transfer element of the conditioner and heating medium to the external heat transfer element. During the heating season the secondary circuit is reversed to supply heating medium to the main conditioner heat transfer element and cooling medium to the external heat transfer element. 7 a

The auxiliary heat transfer element is arranged to be connected to receive fluid from the secondary system to treat the air flowing through the auxiliary chamber and change its temperature in a direction opposite to that of the change of temperature of the air flowing through the main chamber. However, the auxiliary heat transfer element is normally inactive and is supplied with heat exchange medium only in the event that one or more of the enclosures to be conditioned requires a change of temperature opposite to that of the other'enclosures. This arrangement makes it possible to heat one or more oi the rooms during the cooling season and to cool one or more of the rooms during the heating season. During the cooling seasomwater is circulated'over the outdoor heat transfer element to provide evaporative cooling. During the heating season, should the temperature of the outdoor air fall below a predetermined value the circulation of air over the outdoor heat transfer element is stoppedand water from the city mains or other suitable source is circulated over the outdoor element to provide a source of heat at a suitable temperature.

Referring now to the drawings, the air conditioning system shown in Fig. 1 comprises a housing III through which air is circulated .by a fan driven by a motor l2 and is delivered to'a plurality of rooms l3, l4 and I5 through suitable ducts l6, l1, and I8, respectively. Air is supplied to the housing l through a fresh air inlet duct is and through return air ducts 25, 2|, and 22 connected to receive air from rooms I3, I 4, and 5, respectively, the air from the ducts |!,25, 2|, and 22 being mixed and delivered to the fan through an inlet connection 22. The housing I0 is divided into two chambers, amain conditioning chamber 24 and an auxiliary conditioning chamber 25, chambers 24 and 25 being arranged in parallel'with respect to the air flow and being provided with extended surface-heat transfer elements or coils 25 and 2|,"respectively. The duct I is provided with a branch" |5a for receiving air from the chamber 24 and a branch lib for receiving air from the chamber '25. Dampers 28 and 29 are .provided in the duct I51: and lib, respectively, to proportion the amounts of air from each of the chambers 24 and 25 which are to be admitted to the room I: through .the duct lit. The dampers 28 and 29 are linked together so that as-oneof the dampers moves toward its open position, the other moves toward its closed position. The dampers are posi |8a and |8b connected in the same manner as .the branches of the duct ll. Rooms l4 and I5 may thus be supplied with air ,from either or both of the conditioning chambers 24 and 25. The room I4 is provided with a thermostat 34 of the same type as the thermostat 3| connected to receive compressed air from the supply line 22 and to deliver air. under varying pressure through a connection 35 to a bellows 35 which controls dampers 31 and 32 corresponding to the dampers 22 and 25 controlled by the thermostat 3|. Similarly the room I5 is provided with a thermostat 39 and arranged to receive air from the-supply line 52 and deliver it through a connection 45 to bellows 4| which controls dampers '42 and 43 in the ducts Ila and Ilb, respectively.

The main conditioning coil or heat transfer element 25 is connected to receive either heating or cooling medium from a supply line 44 and the auxiliary conditioning coil or heat transfer element 21 is normally inactive, but is arranged to receive either heating or cooling medium through a line 45 in a manner later to be described. 'Normally, therefore; the .air flowing through the chamber 25 is at the temperature or the mixturedelivered to the Ian M, whereas the air flowing through the chamber 24 is conditioned to heat the air during the heating season and to cool the air-during the cooling season. It follows that the dampers", 31 and- 42'should move to an open position on a demand for a decrease in room temperature durlngthe cooling season and on a demand for an increase in room temperature during the heating season. In order that the pressure in the bellows 35, 35, and 4| may be de-- creased on a rise in temperature during the cooling season and on a fall in temperature du'rlng'the heating season, the thermostat must be of a type which may be changed from winter to summer operation. This change-over maybe elected in the thermostats illustrated by providing two available pressures of the compressed air to be delivered to the thermostat through the supply line 32 and by connecting the-supply line to receive air at one pressure duringthe winter andat a different pressure during the summer. The details of the construction and operation of a thermostat of this type are disclosed inPatent No.

2,021,263granted November 19, 1935; to Carl A.

Otto.

In order to supply either. heating or cooling medium to the heat transfer element, I provide a refrigerating machine 50 comprising a refrigerant compressor 5| driven by a motor 52 and arranged to deliver compressed gaseous refrigerant through a connection 53. to a condenser or heat dissipat ing element 54. Compressed gaseous refrigerant tioned automatically by operation of an expansible bellows 30 under. control of a thermostat 3| in the room IS. The thermostat 3| is-of the pneumatic type and is arranged to receive compressed air through a supply line22 and to. de-

liver air under pressure to the bellows 32 through a connection 33, the pressure in the connection 35 being varied in accordance with thetemperature of the air in enclosure l3. The ducts I1 and I! are provided with branches Ila and "b and is cooledand liquefied in the condenser 54 and the liquid passes through a liquid line and a heat exchange coil 55- to an evaporator or heat absorbing element 51 through a float controlled expansion valve 53 The valvell. is operated by a float 59 to maintain substantially constant the level of. liquid refrigerant in the evaporator as indicated at 50. Liquid refrigerant in the evaporator isvaporized by the absorption'of heat and the vaporizedrefrigerant flows through asuctlon line 5| and a casing 62 about the heat exchange coil 55 backto the compressor "through a connection 53. i

"me refrigerating machine In is employed as a heat pump which is'controlled selectively to pimp heat from the outdoor air. to the air in the chamber 24 or from the air in the chamber 24 to the outdoorwair depending upon the seasonal the cooled by the evaporator year. In order to absorb heat from or dissipate heat to the outdoor air, an external heat transfer element or heat exchange coil 64 is housed in a duct or casing 65 through which outdoorair-is circulated by operation of a fan driven by an electric motor 61 In order to connect the evaporator and the condenser of the refrigerating machine to either of the heat exchange elements 28 and 84, I providea secondary system for circulating a heat transfer medium such as brine or some other suitable non-freezing liquid through the heat exchanger coils anddn heat exchange with the refrigerant in the. condenser 54 andin the evaporator 51. The secondary system is arranged so that it provides, in effect, two closed circuits, one including the condenser 54 and the other including the evaporator 51. The condenser circuit includes a pump 88 driven by an electric motor 88 and'is arranged to be connected to deliver liquid heated by the condenser to'the element 26 during the heating season and to the element 64 during the cooling -season.- The evaporator circuit includes a pump 18 driven byan electric motor 1| and arranged to deliver liquid to theelement 26 during the cooling season and to the element-64 during the heating season. i

The evaporator 51, com-prises a main refrigerant chamber 12 and an inlet chamber 18 and an outlet chamber I4 connectedby a plurality of parallel pipes 15 for circulatingv the brine o'r other heat transfer medium in heat exchange relation with the liquid refrigerant in the chamber 12. The condenser 54 is constructed in.a manner similar to the evaporator 5l'and comprisesa main condensing chamber 18 where the compressed refrigerant is liquefied, and the brine iscirculated through the condenser from an inlet header 'I'l through a plurality of parallel tubes 18 40 Suitable reversing valves. 88, 8|, 82,-a nd 83 are to an outlet header 18.

provided to control theqmain'connections of the secondary circulating system to determine the direction of heat transfer between the heat exchange elements 2.8 and 84., In thedrawings the reversing valves are the cooling season. During the cooling'season the pump 10 circulates heat transfer liquid cooled by the evaporatorthrough the upper port of the valve 8| to the heat exchange element 28 where.

the liquid absorbs heat from the air circulated through the chamber 24, ,The warmed liquid is returned to the evaporator through the upper port of the valve '88 and is again cooled by circulation through the pipes 15. 'I'he'heatv 'absorbed by the refrigerant within the evaporator is carried by the vaporized refrigerant to the compressor and is then conducted to the condenser with the compressed refrigerant. The compressed refrigerant is cooled and liquefied by heat exheat transfer liquidflowing through the tubes 18. The heat transfer liquid in the condenser tubes 18 is thus heatedand is circulated by the pump 68 through the lower port of the valve 83 andthrough anormally open valve 84 to the heat exchange element 84 where change with the it is available to heat the outdoor air passingthroughthe casing 85. The heat transfer liquid returns. from the element-84 to the condenser through the lower port of the valve 82.

and through the upper ports of the valves 82 and 83. The pump 18 circulates liquid cooled by the evaporator. Slthrough the heat exchange element 84 to absor heat from the outdoor air 85 and the pump 88 circulates heat transfer fluid heated by the condenser through the-heat exchanger 28 so that the heat is, supplied to the air flowing through the main conditioning chamber 24. 8

During the heating season when the outdoor temperature is well below freezing it Will readily be understood that the required heating'capacity of the machine is greater but-since the differential of temperature between the heat exchanger and the outdoor airis small the transfer of heat is inefllcient. I have provided an arrangement which under these conditions circulates water from the city water mains or other suitable, source over the surface of the outdoorheat exchange coil 84; and in order to prevent freezing of water in ,the casing 85, dampers 85 and 86 are provided to shut off the circulation of the cold out,- door air through the casing 55. The arrangement for circulating water comprises a. valve 81 actuated by a normally inactive bellows 88 which opens the valve only when the outdoor. temperature is abnormally low,

. water from the city mains or supply indicated at 88 through a pipe 88 to a spray-head 8| mounted over the heatexchange coil 84. The water, after being circulated over the heat exchanger-coil, flows to a sump 82 at the bottom of the casing Giraud thence through a drain connection 83 -to the drain through a valve 84 which is opened during the sprayingbperatlon.

For. operation during the cooling season particularly when the outdoor temperature is high,

shown in theirpositions for During the heating season the positions'zof the reversing valves 88, 8|, 82, and 88 are reversed by operation of a control which will be described later, and the heat transfer fluid is circulated through the lower ports of the valves-88 and 8| cost of circulating city waterfover the I provide an arrangement for spraying water over the heat exchange coil 84 so that it operates as an evaporative cooler. The evaporative spraying arrangement utilizes the spray-head 8| and a pump 85 driven by an electric motor 88 which circulates water, from the sump to the'spray-heacl 8 I The level of water in the sump is maintained substantially constant by operation of a float controlled valve 81. During the' cooling season the valve 8.4 iskept closed so that water may be maintained at a desired level in the sump 82. I The valve 81 is also-closed so that city water is not circulated to the spray-head 8|, however, makeup water is supplied to the'sump from the source 88 by operation of the valve 81. Byemploying the pump 85 and continuous circulation of the water from the sump, it is possible to effect considerable economy in theluse of the water over the coil 64 and wasting it to the drain. I

The several rooms of a building may have wide v ly varying heating and cooling loads and particularly during milder weather some rooms in the building may require heating, whereas others may require cooling. For example, the rooms on. the sunny side of the building will be heated more than those on the shady side. Other conditions may arisewhere a large number of people in a room or some apparatus which operates at a high temperature may require'that the room be cooled in order to'obtain' comfortable conditions during the heating season.

shown in the drawings, Ihave provided an arrangement whereby one or more .rooms may be supplied with air the temperature of which has been changed in a direction opposite to that of the main stream of conditioned'air; Referring again to Fig. 1, the heat exchange element of coil and controls the flow of In the apparatus I nection I 03 21 and heated ing closed and the damper 21 isvconnected in the secondary circuit in a bypass around the coil 64 which includes a pump 98 driven by an electric motor 99. The by-pass circuit is thus arranged to receive heat transfer fluid from a portion of the secondary cireu'it such that it will change the temperature "of the air flowing-through the chamber 25 in a direction opposite 'to the change of temperature oi the air v I flowing through thechamber 24. I operation of the air conditioning system. the ducts During normal l6b, I 112 and I86 are supplied with air at the tem-v perature of the mixture of air in the casing i and the several sets of-damp'erssupply air to the ducts l6; l1, and i8- at suitable temperatures which are attained by mixing air from the chamber 25 with air'fromthe chamber 24. Should one of the'sets of 'da'mpers movers 'a position in which all the air delivered to its main duct is taken from the chamber 25"th'is would be an indication that the change of" temperature required in the corresponding room is opposite to thatj'i'or which the main conditioning system is setto operate. In the system illustrated it isassumed thatroom ll may require heating during the that the room I may require cooling during the heating season; 1 I

With the apparatusseti'or the coolingseason as shown in the drawings, should there be a demandfor heating, as determined by, the thermostat in the room llwhichwill then position its dampers to admit air only from ductjll b, the motor 99 will be energized to operate the pump 98. The pump 98 will deliverto the coil 2] heat transcooling season and connection IDS:

fer fluid which has been circulated from the condenser through'the' lowerport of the valve 83, and then through'a mixing valve I to the pump 98; Liquid after circulating thrOllgh the heat exchanger 21 returns to" the condenser "circuit valve i02 to'prevent reverse flow. A branch con-v closed by the valve IN in its lowermost position as shown. The heat exchanger coil 21 is thus] connected in a by-pa'ss inthe secondary circuit of.

the condenser. The air circulated through the I chamber 25 is 'now'heated by the heat transfer coil air is delivered to the ducts lib.

"b, and 18b, and the several'dampers' will adjust :their positions accordingly, heated air now being available for delivery through the duct lib to the room l4. Under this condition oi. operation the temperature of the water flowing through the condenser andconsequently the temperature q or. the water flowing through the coil21 is controlled by a reverse acting thermostat I05 having a thermal element I06 responsive to the temperature of the water delivered from the condenser by'the pump 68. e 84 'andthereby determines the proportion of the heat'transfer liquid which is to pass through the outdoor heat exchange coil remainder of the fluid to heat is absorbed by the air flowing through the demand for coolingin'the room. [5 as deter-.

provided'with'a check valve IM-is The thermostat l05controls the valve" changing the room 5 thermostats summer operation, theichange being eflected" by supplyin air at; either'of two' predetermined I control valves-iii and a controlvalve 5.1,1hepressureniainmay-the 20 pounds per a '50 7 pounds per square inch": The room thermostats' has already-been stated are 01- the summer winter type; .-they are: arranged to operatenas coolingqthermostatm when the pres sure in the line" 32 .is- 12 spounds and asheating pressureis 20 pounds.) The changeoversot' the system -'as a whole from" its setting fox-.thecoolirig season to its setting season, and vice versa,is accom-- plished by operation' of va valve or-pneumaticthermostats when-the 64 to be c ooled, tl ie be cooled passing: through the heat exchanger coil 21 where its;

to the pump 98 at "some heat exchange tained by. the. valve H 2 the heat tran er coilYz'i; The temperature Qo'l the water delivered to the pump 7 98 is "controlled by the mixing valve I M. Thevalve i 00 is actu ated by a thermostat i01 having-a thermal element' or "bulb' 'Illl responsive to the-temperature of the fluid delivered to t-hepump 9l. The thermostat m is set to maintain the iiu'id dehver'ed such as 40' F., the contr lot the temperature being accomplished by mix'inghportion oi 'the' liquid flowing directly from the pump-ll with another 1 portiori'whicn has been J warmed by the coil 'liand flows to the= valve iflll through the "I'he check-valve l'Misfprovided to prevent back iiow thi-oug'hthe conduit Ill. The thermostat I01 maintains the valve I 03 in its iullopen position'as shown unless'the tern- 401 t The entire system-is controlled automatically so that-a changeover of the mainconditioning system from I heating' to cooling, as wellas the supply of heating or cooling fluid tothe auxiliary coil 21, willbe' accomplished in accordance-with the load demands or the system as determined by suitable-thermostats in the several rooms v in the supply ducts. The manner system operates and is controlled will now be explained'with the assistance of the control diagram shown-iirFigt 2;

The-control system as shown-inFig. 2 is of the pneumatic type, the operating air {at a suitable -pressure,1'say' 25*pounds per; square inch,

being supplied from a suitable source through-a connection ll/l. Airat-suitable pressure for-the operation ofthe :system is supplied through a' main pressure supply line "on conduit- I ll, presthrough a'connection lol provided with acheck sure control valves e and: H3 being; provided to 1 maintain. a predetermined desired constant the conduit 1.: 'I'heair line airv to the room' thermostats is provided for pressures determined by; the

square inch 'forexample and that maintained by the, valve I 15 may be 12 inch. A valve! 32 selectivelyto 3], 34. and as for the heating relay I ll which. is connected :to' receive pressure from the. supply "line. HI;

cooling or seasonal changeover line I II by the valve ill'in its open position." whenlpressure minedby the thermostat ilthedamper 42 bei by the evaporator to prevails inthe line: ,I I! v the several :controls connected thereto arev set cooling operation-of through a port or orifice H9 and releases the suitable temperature perature at the bulb or element I" falls below or other enclosures, in-the 'outiroin winter to pounds .per square is provided to connect the line receive. air at either 12 I or I Duringthe cooling season the supply line'lpressure of '15 pounds per squareinch is applied directly to a heating in their positions forvtthe the system Whom-the I valve 1 i 1: moves to its'closed position it connects the line Ill directly with the. atmosphere the system the room I4 heat'and the increased pressure of this pressure is underpressure from to bellows I40 or a relay I4I,

pressure on the, control devices, thereby setting them in their positions for the heating operation of the system M I20 and I2I arearranged in the from the rooms is deliv- Thermostats return ductto which" air ered by the'ducts20, 2I, and 22. The thermostat I20 is placed in operation during the cooling season and the thermostat I2I is placed in the heatingseason.- The theroperation during mostats I20 and I2I are arranged, to actuate a relay I22 by controlling he pressure in a bellows I23 of the relay. The'thermostats are; connected to the'relay'throu'gh a valve I24 which is actu-.

I25 connected to receive presated by a bellows sure from the changeover line-I18. During the cooling season there is pressure in the line H8 1 and the bellows I25 expands tomove the plunger of valve I24'to its upper-positionthereby connecting thethermostat I to the bellows I23 through the lower port of the valve. When presblower motor I2 which is connected across the lines I28 and I29 and thereby starts theoperation of the blower II to circulate air through the casing I0 and through the several ducts of the system. The compressor motor- 52 and the pump motors 69 and H are also started provided normally closed switches I32 and I33 are in their closed positions and the outdoor fan motor 61 will also be started provided the outdoor temperature isabove a predetermined value such as 20- F. as determined by a thermostat'l34 which operates a switch I36 by means of a bellows I36. The water circulating pumpx 96 will also be started to spray waterover the outdoor "coil 64. When the several motors are running,

the system is inoperation ior cooling and the thermostats at; u, and 33will operate individually to position their; corresponding dampers so that the desired predetermined temperatures are maintained in the rooms I3, I4, and I5. Under this. condition of operation heat transfer fluid cooled bythe evaporator is being supplied to the coil 26 to cool'the air in the main conditioning chamber 24 and the air passing through the auxiliary chamber is at'the temperature of the mixture of air supplied to the blower II.

It may happenthat during the operation of will become too cool for comfort. For example, this. room may be on the shady side of the building and have relatively few sources of heat within it so thateven air at the temperature of that supplied from the auxiliary chamber 25 will be too cold for the room I4. Under this condition the thermostat 34 will have operated so that the bellows 36 has expanded and moved the damper 31 to its completely closed position and the damper 38 to its completemechanism'is an indication'that room I4 requires air supplied by the thermostat 34 to the bellows supplied to a bellows I31 of a relay I38; and when sumcient to indicate a heating demand the relay I38 pressure through the liquidiin the coil {and supply heated air 'the room I4 may be maintained at its desired temthe line III and supply it will actuate from the line I the relay HI and supply air at a pressure controlled by the relay through the.

upper port of a valve I42 to a bellows I43. When the pressure in the bellows I43 reaches apredee v -termined value, the bellows I44 and start the operation .of the by-pass pump will close a switch motor 99 to drive the pump 9 8 and circulate heatedliquidithrough the coil 21. 'This will heat the air passing through the auxiliary chamber 25 to the duct no so that perature. Pressure will also be supplied by the relay I4I tea bellows I45 and will actuate a valve I46 to connect the under'pressure from the line II8 through'the upper port or the valve I46. The thermostat I05 then controls the'valve 84 through a bellows I41 tomaintain the ,te mperature of the liquid supplied from'the condenser at the desired value of 90 F. "If the temperature falls 'below 90 the thermostatincreases thepressure in tthe bellows I41,whichexpands against the pressure of a spring I41a and moves the valve toward its closed position. [The relay I also supplies air under the upper port of a valve I48 to a bellows I43. The bellows I49 expands under pressure and opens. a switch I50 to deenergize the motor 96 and stop the operation of the spray pump -35. This stops the ,evaporative cooling of 64 so thatthe desired higher temperature of the liquid may be maintained by operation of the thermostat I05.

The operation of the by-pass pump 90 to supply heated liquid to the coil 21 will be continued as ly open position. This position of the damper 36 is also will open to admit air long as the thermostat 341maintains a' sufilciently highpressure' of the, air in the bellows I31. when this pressure falls the positions of the several relays and operating bellows will be restored to their positions as shown in Fig. 2., The pressure in the bellows I43, I45, and I48 is released through a vent port I5I ofthe valve MI, and the pressure in thebellows I40 is released through a vent port I52 of the valveI38.

During the normal. operation of the cooling season the thermostat I20 maintains suflicient pressure in the bellows I23 to keep the relay valve I22 in itslower'position sothat air 'at'15 pounds pressure from the line III is delivered through a restrictor I55and a receiver I56 to a bellows I51 of a relay I58 and also to a bellows I59 of thevalve H1. The pressure in the bellows I51 and I5I-maintains them in their expanded positions so that the relay valve I58 is closed and its lower chamber is in communication with the atmosphere through a port I60 and so that the valve II1'is H9 is closed. When the relay'I58 is in the position shown, bellows I 6I and I62 which operate the switches I32 and I33, respectively, are in their I collapsed positions and aintain the switches closed. The relay I58 includes a valve member I51a for controlling the rate of flow of air through the relay and a valve member Ia for controlling the discharge of-air to the atmosphere. The valve I800 is pressed upwardly by a spring to close the opening I60 when the stem of valve I611; is moved upwardly by contraction of the bellows I51, the valve I800. being separate from the stem of the valve I51a so that the opening I60 is closed when thevalve I51a starts to open'and regulate the flowof air through the relay.

Should the temperature of the air returning thermostat I05 to receive air the system in open and its discharge port temperature the mostat ill to the changeover line ii. will telripel'ature has risen to a main conditioning chamber 24 from the rooms and flowing over the thermostat III tall below a l"., it would indicate that the system shouldbe over from cooling to heating. At this pressure delivered by the therbellows v IN compresses the bellows and moves the relay to its upper position shuttingoi! the connection and the pressure line I I l exhaust the line ill to through the exhaust port Ill The pressure in the seasonal then fall to zero and the changed over from its cooling setsetting. The bellows III will the valve ill so that the control by the atmosphere of the relay' I I1.

systemwillbe receiver I" is completely exh the port i, the bellows convalves move to the tions from those in which they are l, and connectthe secondary-fluid circuits in their heating positions. The valve III is also moved to its upper position by the contraction or an I" and the line 32 is thereby connected through the lower port 01' the valve Ill so that its prestract and the positions since their corresponding bellows I and I", respectively, are connectedwith the line lllandcontractonreleaseofpressure'.

Since the air in the chamber)! isheated the damper mechanisms controlled by the several room thermostats must p by. their thermostats in accordance with the havingbeen en'ected, in the bellows Ill and I82 will fall to zero and the switches I32 and-III will be closed-in sequence.-' The bellows it! will remain contracted and the relay llr'in its upper position'until the thermostat m indicates that the the pressure say .75-F., and that there should be a changeover from heatingto cooling operation. r The system, when in its heating setting, will operate to supply hot fluid to the heat transfer coil and heat the air predetermined value, say 72* llflalls so that a spring shown in Fig.-

mech

operating bellows,

predetermined value, a

7 through the chamber 25 II, N and it, and operate their corresponding anisma tosupply air at the reto these several enclosures.

Ill thereby discontinuing tor II and also .deen

heat irom the city water which is cooled and flows to the sump I! from which it is drained through connection It and valve II. The valve 34 has a bellows I'll connected to the seasonal oi the outdoorblower motor OI, I

Ii during the heating season the temperature in the room II should increase termined value, as determinedby the thermostat ll, such that the damper 42 is completely closed and the damper ll completel is now'cooled, all the damper mec will readjust their positions to maintain the desired temperaturesin the sev above a prede 52 C1, 89, and II.

mand of the greater number "of'roor'ns,

- in a direction opposite vsite erai rooms. "rhe temperature of the liquid circulated through the 'by-pas's'secondary system by operation oi the pump 98 will be controlled by the'thermostat Illl whichv actuatesthe mixing valve Hill. The thermostat IIIldoes'not operate,

since the expansion of the bellows I45 merely operates the valve I46 to connect the thermostat with the seasonal changeover line, which the bellows I11 will contract and the pressurewill be released from the bellows I. and I through a discharge orifice I19 of the relay.

The operation of the system to providexheating' will continue throughout the heating season until. such time that thereturn duct thermostat I2I' supplies pressure to the bellows I22 of the relay I22 at'a value indicating that the temperature has risen to such a'value that cooling is required. When this occurs, the plunger of relay 'I22 will move to its lower position and connect the receiver I55 to the pressure supply line I through therestrictor I55 As the pressure builds up bellows I59 will expand to shut ofl the dischargeoriilc'e II! and supply pressure to the seasonal changeover pressure continues to rise I62 will expand to open in sequence and deenergize the compressor motor 52 and the pump motors 68 and II, as well as the outdoor fan motor 51. As the pressure continues to rise the bellows I51 will expand and actuate the relay I58 to open the discharge orifice I60 thereby releasing the pressure from the bellows ISI and I62 and again starting the motors Since the seasonal changeoverline is now under pressure the system is operated on its cooling; cycle the several controls being againin their positions as shown on the drawings. Y

the bellows IiI and During the operation oithe system as above described the controlwill automatically select themost desirableoperating setting, so'that the systemwill supply heat transfer liquid either heated or cooled depending'upon the load de- I and those to have a conditioning load to that normal during. the may be supplied with air the temperature rooms which are apt season,

oi which has been changed in a direction oppoto that of the main air supply.

1 While I have described and illustrated my vention' in connection with i'a particulartype of air conditioning system, other applications will readily be apparent to those skilled in the art. I do not, therefore; desire my invention to be limited to the particular construction-shown and described, and I intend in the appended claims Letters Patent of the United States is:

'1; Apparatus for heating and cooling the air in aplurality'ot enclosures comprising areirigmeans providing two air circuerating machine,

for circulating air through lating paths, means .said paths andinto saidenclosures, saidiimeans being so arranged that each of said enclosures refrigerating machine, a heat transfer element in the other of said paths, and'means dependent upon a condition of the airin at least one of 7 said enclosures for ing two chambers" selectively raising of said chambers,

line Ill, and as the 30. the switches I32and I33 of said: chambers .the air passing through said connecting said last mentioned heat transfer element to receive'from said refrigerating machine heating or cooling medium of the opposite temperature characteristic from that selected to be supplied to said first mentionedheat transierlelement.

2. Apparatus for conditioning the air in a plurality-oi enclosures comprising means includand a plurality of ducts for conducting air from both of said chambers to each of ,said enclosures, separatemeans asso-' ciated with each of said enclosuresior proportioning therelative amounts of air fromieach corresponding ones ofsaid enclosures, meansfor or loweringjthe temperature oixthe. air. passing through one of said chambers, means for selectively raising or lowering the temperature of the air passing through the other said last mentioned means being normally inactive,- and means dependent upon the setting of at least one of said proportioning means to'conduct air to its corresponding enclosure solely: from saidother chamber for rendering said normally inactive means effective to change. the temperature of the air passing through said other chamber in a direction opposite to. that 0! the change in temperature of one chamber.

3. Apparatus for conditioning the air in a plu- -r ality of enclosures comprising a refrigerating machine for supplying heat transfer medium for heating and for cooling, means including two chambers and a plurality of ducts for conducting air from both of said chambers toeach of said enclosures, individual means for proportioning the relative .amountsof .airfrom each of said chambers which are conducted to each of said enclosures-a heat-transfer elementarranged in ,oneflot said chambers and connected toreceive heat transier-medium from said refrigerating machine for selectively raisingor lowering the temperature of the air circulated through one or said chambers, a normally inactive heat transfer element ,arrange'din the other of said chambers,

' and, means dependent .upon'the positioning or at least one oi. said individual proportioning means to conduct air solely. from said other of said chambersto the corresponding one or ones of said enclosures for connecting saidnormally inactive heat transier elementto receive heat transfer medium from said refrigerating machine for changing the temperature of the air cir' culated through said. other chamber in a direction opposite to that of the change in temperature-ot theair circulated through said onecham- I to cover all modifications within the spirit and may receive air from both said Ipath's, a heat transfer element arrangedin one or said paths; means .for selectively connecting'said element her. a I 4. Apparatus'mr conditioning the air in, a plurality of enclosures comprising means for .sup-

plying air to each of said enclosures, said means including a main duct and an auxiliary duct for eachenclosure, damper means associated with each'enclosuredor proportioning the relative amounts of airto be. conducted through the main duct the auxiliaryduct to the enclosure, means for raising or lowering the temperature of the. air passing through said-v main ducts, means for raising or lowering the temperature of the air passing through said auxiliary ducts, said last mentioned means being normally inactive, and means dependent upon the-setting of at least onefoi' said damper means to conduct air .which are conducted to the change relation with said to supply heat to said refrigerating machine, norsolely from its corresponding' auxiliary duct for rendering said normally inactive means effective to change the temperature of the air passing direction 011- posite to that of the change in temperature of, the air passing through said main ducts. I

through said auxiliary ducts in a 5. Apparatus for conditioning the air in a plurality of enclosures comprising two chambers and a plurality of ducts for connecting both of said chambers to each of said enclosures, means including proportioning dampers associatedwith chambers to the of said chambers, positioning of at conduct air solely the corresponding and means dependent upon the one of said enclosures for renones of said enclosures, means for raising or lowering'the temperature of the air passing through one of said chambers, means for raisingor lowering the temperature of the air passing through the other of said chambers, said last mentioned means being normally inactive, means operative during the cooling season and dependent upon a said proportioning I means effective to heat the air passing throughsaid other chamber, and means operative during the heating season the setting ofa different other chamber for rendering said normally inactivemeans effective to cool the air passing through said other chamber: i

7. Apparatus for conditioning the air within an enclosure comprising a refrigerating machine having a heat absorbing means and a heat dissipating means, means for utilizing said heat dissipating means to heat the air in the enclosure, means-forcirculating outside air in heat exheat absorbing means mally inactive means for conducting water in heat exchange relation with said heat absorbing means to supply heat to said refrigeratingmachine, and meansadependent upon a predetermined low temperature of the outside air for preventing the circulation of outside air inheat exchange relation with said heat absorbing means and for rendering said normally inactive means eflective to conduct water in heat exchangerelation with said heat absorbing means to supply heat to said refrigerating machine. j

8. Apparatus for conditioning the air within an enclosure comprising a refrigerating machine 76 least one of said dampers to" from said other chamber toan enclosure comprising sipating means,

prevent the admission air from said having a heat absorbing means and a heat dismeans forutilizing said heat disof outside air to said housing and for rendering said normally inactive means eflecti've to circulate, water over said extended surface.

9. Apparatus'for conditioning the air within a reversible refrigerating drefrigeratingmachine is connected to heat the air in theenclosure'for actuating said normally inactive means and for actuating said means for;. enclosing said second heat transfer means whereby heatifor said refrigerating machine issu'pplied from the source of water;

10. A system for conditioning the air in aiplurality' of enclosures comprising a casing having two chambers therein,-means for withdrawing enclosures :andfor supplying the to said casing; a main conditionwithdrawn air ing coil in o of said chambers, means, for, supplying to each ofsaid enclosures from both of said chambers, individual temperature responsive means said coils, upon the temperature of the air from said enclosures supplied to said casing for selectively operating said refrigerating machine-to supply heatingsor cooling medium tos'aid malnj conditioning coil, and means dependent upon the tem. perature of the e of said chamberalanormally said main coil in the temperature of the air circulated through said one chamber.

11. Apparatus for conditioning the air within an enclosure comprising a reversible refrigerating machine having a first heat transfer means for heating or cooling the air within the enclosure and a second heat transfer means for absorbing heat from and for dissipating heat to the outside air, selectively operable means for connecting said refrigerating machine for heating or for coolingthe air in the enclosure, means for circulating outside air over said second heat transfer means, a spray-head for directing water over the surface of said second heat transfer means, means dependent upon the connection of said refrigerating machine to cool the air in said enclosure for collecting water circulated over said secondheat transfer means and for recirculating the water to said spray-head whereby said second heat transfer means operates as an evaporative cooler, normally inactive means for connecting said spray-head to a source of water supply, and means dependent upon a predetermined low temperature of the outside air when said refrigerating machine is connected to heat the air in the enclosure for actuating said normally inactive means whereby heat for said refrigeratingmachine is supplied from the source of water.

12. Apparatus for conditioning the air in a plurality of enclosures comprising a refrigerating machine for supplying heat transfer medium for I said chambers, a second heating and for cooling, means including two I chambers and a plurality of ducts for conducting air from both of said chambers to each of said enclosures, individual means for proportioning the relative amounts of air from each of said chambers which are conducted to each of said enclosures, said refrigerating machine comprising a compressor and a condenser and an evaporator, a first heat transfer element in one of heat transfer element arranged externally of said chambers, means for circulating a heat transfer fluid over said second heat transfer element for absorbing and for dissipating heat externally of said chambers, a first fluidc'ircuit including said first element, a second fluid circuit including said second element, means for selectively connecting said evaporator and said condenser in heat exchange relation with saidfluid circuits whereby the condenser isv in heat exchange relation with said firstv circuit when said evaporator is in heat exchange relation with said second circuit and vice versa, 9. third heat transfer element in the other of said chambers, normally inactive means including a third fluid circuit-by-passing a portion of said second circuit for supplying heat transfer fluid to said third element which has a heat characteristic oppositeto that of the fluid supplied to said first element, and means dependent upon the positioning ofat least one of said individual proportioning means to conduct air solely from said other of said chambers through the corresponding one or ones of said enclosures for rendering active said normally supply heat transfer fluid to said third element. STEPHEN A. DURBIN.

inactive means to 

